Nowadays, the portable display devices are getting more and more popular for its portability. A watch, especially an intellectual watch, already can run application software, and can achieve more functions, and can be used as a mobile electronics. However, for an intelligence watch, the screen thereof always has less area which makes it difficult to meet some of the consumer's demand, for example, watching movies, and etc., this has become a great drawback that restricts developments of the intelligence watches.